Influence of Incomplete Soil Plugs on Bearing Capacities of Bucket Foundations in Clay

• Published in: China ocean engineering 2024-02, Vol.38 (1), p.144-155
• Main Authors: Li, Hui-shan, Liu, Run, Yang, Xu, Lian, Ji-jian
• Format: Article
• Language: English
• Subjects: Coastal Sciences; Engineering; Fluid- and Aerodynamics; Marine & Freshwater Sciences; Numerical and Computational Physics; Oceanography; Offshore Engineering; Simulation
• ISSN: 0890-5487; 2191-8945
• DOI: 10.1007/s13344-024-0012-3

Due to the uneven seabed and heaving of soil during pumping, incomplete soil plugs may occur during the installation of bucket foundations, and the impacts on the bearing capacities of bucket foundations need to be evaluated. In this paper, the contact ratio (the ratio of the top diameter of the soil plug to the diameter of the bucket) and the soil plug ratio (the ratio of the soil heave height to the skirt height) are defined to describe the shape and size of the incomplete soil plug. Then, finite element models are established to investigate the bearing capacities of bucket foundations with incomplete soil plugs and the influences of the contact ratios, and the soil plug ratios on the bearing capacities are analyzed. The results show that the vertical bearing capacity of bucket foundations in homogeneous soil continuously improves with the increase of the contact ratio. However, in normally consolidated soil, the vertical bearing capacity barely changes when the contact ratio is smaller than 0.75, while the bearing capacity suddenly increases when the contact ratio increases to 1 due to the change of failure mode. The contact ratio hardly affects the horizontal bearing capacity of bucket foundations. Moreover, the moment bearing capacity improves with the increase of the contact ratio for small aspect ratios, but hardly varies with increasing contact ratio for aspect ratios larger than 0.5. Consequently, the reduction coefficient method is proposed based on this analysis to calculate the bearing capacities of bucket foundations considering the influence of incomplete soil plugs. The comparison results show that the proposed reduction coefficient method can be used to evaluate the influences of incomplete soil plug on the bearing capacities of bucket foundations.